A high-performance oxygen detection system enables real-time online monitoring of critical parameters such as oxygen concentration and flow velocity within the engine, ensuring optimal operational efficiency. In flow field tests for engines such as scramjet and aviation engines, the complex environment characterized by high temperatures, pressures, and velocities, along with limited measurement space, poses significant challenges for accurate flow field diagnostics. To address these challenges, a device for measuring oxygen component concentration based on cavity-enhanced absorption spectroscopy (CEAS) was developed. The device features an embedded optical probe design and incorporates multi-directional adjustment mechanisms at both the transmitting and receiving ends to facilitate precise optical path alignment, enhancing its applicability in engineering experiments. Experimental results demonstrated that, in a static environment, the measured oxygen concentration was 20.846?0.97%.. In shock tube experiments, the system successfully captured three distinct states: before the arrival of the incident shock wave, after the passage of the incident shock wave but before the reflected shock wave arrived, and after the passage of the reflected shock wave. The measured oxygen concentration data were consistent with theoretical predictions.